• In order to initially generate a FICO score, you must obtain lines of credit from companies which report payment activity to at least one of the the three major credit bureas: Experian, Equifax and Transunion. This results in tradelines which cause your score to fluctuate depending on financial diligence or missteps. The FICO score ranges from 300 to 850, with the best interest rates and loan options available to those with scores in the 700s. In today's credit-driven society, the FICO score is very important, because this is what lenders, landlords, credit card companies and even employers use to determine your worthiness and risk level. To maintain good credit, it's imperative you know the various activities to avoid which lower FICO scores.
  
  

Payment History

• Making late payments on credit cards, car loans, rent or a mortgage will negatively impact your score. Payment history has the biggest impact on a FICO score, accounting for 35 percent of your credit grade, according to SmartMoney.com. Payments are considered late and reported to the credit bureaus after 30 days of non-payment after due date. Credit continues to take a hit every 30 days payments are missed. For example, if you don't make payment for two months, your report will reflect a 60-day late status. The delinquency length will hurt the score more than a 30-day late status would. Also, recent late payments will hurt the score more than older ones.
  
  

Balances

• Carrying high balances relative to the credit limit on cards will negatively impact your score. High balances, or debt load, account for 30 percent of the score, according to MyFICO.com. The amount owed overall matters as well, so spreading the debt over several cards will also negatively impact the score, even if you stay within the lower end of your credit limits. The proportion of amount still owed on loans such as mortgages or auto, will also hurt the score, so it's good to pay down accounts as quickly as possible.
  
  

Length of Credit History

• Having little or no depth of trade (history) will negatively impact a score. Credit history accounts for 15 percent of the score, according to MyFICO. It depends on the length of time you have had the credit card or loan, your loyalty to the company, in other words, as well as the amount of time since you last used it. However, even if you rarely use a specific line of credit, you should still leave it open, rather than cancel it, according to SmartMoney.com. The average length of history of all accounts also factors into the score, so opening new credit and applying for credit can also lower the score.
  
  

Bankruptcy, Judgments and Liens

• Public records such as bankruptcy, judgments and liens can be detrimental to a score. Usually, the higher your score before the action, the much harder the impact to your score, according to MyFICO.com. Bankruptcies, depending on what kind, will hurt your score for a period of 7 to 10 years. Judgments and liens can stay on the report longer if they aren't paid off. Settling an account balance will also hurt your FICO score, although perhaps not as much as a bankruptcy would.
  
  

Misinformation

• Errors on credit reports are very common. They result from identity theft, people with similar names or mistakes by the credit companies. It's important to check your credit report at least once a year, to make sure no one else is assuming credit at your expense or reporting inaccurate information on your behalf to the bureaus.